That's an amazing concept! I really liked being able to shoot sideways, it feels like naval warfare, going around enemies shooting at them. This feels like the kind of game you want to play with both hands on the keyboard, so it might be better if there is no mouse, eg the first key you press becomes forward thrust and so on while you have yet controls to pick. Having a "minimap" of where each key is in the keyboard might be a nice addition, though it could've taken too much time to implement.